Switch back to previous application after "code --wait"

<!-- ⚠️⚠️ Do Not Delete This! feature_request_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- Please search existing issues to avoid creating duplicates. --> <!-- Describe the feature you'd like. --> When using `code --wait` in, for example, Terminal.app on Mac, it would be convenient if it would switch back to Terminal.app after closing the file in VS Code. The `subl` command-line tool of Sublime Text does this, and it's awesome. It has an option to disable this behavior ("-s or --stay: Keep the application activated after closing the file"); I suppose for `code` it could also be the other way round, with an opt-in parameter in order to not change existing behavior. For now I'm approximating the behavior on Mac with a small wrapper script: ``` #/bin/sh pid="$(osascript -e 'tell application "System Events" to get unix id of first process whose frontmost is true')" code -w "$@" osascript -e "tell application \"System Events\" to set frontmost of processes whose unix id is $pid to true" ```